After a lot of playing around it seems that the problem is all about file formats. DLNA (Digital Living Network Alliance) is trying to set an “open industry standards for cross-industry digital convergence” according to the website. Unfortunately it does not seem to support FOSS standards.
I got there formats from their website and it seems correct as I was unable to access anything that was not on this list. My test was not comprehensive but only a sample test of what I had available. Maybe this can be added to the Amahi DLNA Wiki page.
Table 1. DLNA Media formats for Home Devices
Imaging: JPEG, GIF, TIFF, PNG
Audio: LPCM (2 channel), MP3, WMA9, AC-3, AAC, ATRAC3plus
Video: MPEG2, MPEG1, MPEG4, WMV9
This was a real pain for me as all my music is in ogg or flac formats and none are supported. Maybe if this was on the DNLA wiki I would have chosen different file formats. I tried to add it to the wiki but can't. Don't know why.
Maybe there are some of you the understand MiniDLNA that was used for Amahi DLNA as it seems that other DLNAs can access FOSS formats. I don't know.